HTTP 203 Non-Authoritative Information — What It Means & How to Fix It

The HTTP 203 Non-Authoritative Information status code indicates the request was successful but the response payload has been modified by a transforming proxy. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.

Here are the key things to understand: This status code indicates the response metadata is not exactly the same as what the origin server provided.. It is typically returned by a proxy that has modified the response headers or body.. The original response from the origin server would have been 200 OK.. It is rarely seen in practice and mostly theoretical.. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: A transforming proxy modified the response content before forwarding it.. A CDN or caching layer altered response headers.. Content adaptation or compression by an intermediary.. Identifying the root cause is the first step toward finding the right solution.

To resolve this, follow these recommended steps: If you need the original response, bypass the proxy and connect directly to the origin.. Check proxy and CDN configurations for content transformation rules.. Compare the response with a direct request to the origin server.. Review the Via header to identify intermediary servers.. If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.

This article is part of our HTTP Status Codes collection on Error Codes Wiki. We provide comprehensive, up-to-date information to help you find solutions quickly.